The present invention is concerned with display cards of the types employed as greeting cards and also those used for advertising and similar purposes. More particularly, it is directed at display-changing or scene-changing cards, and especially the kind usually described as pull cards.
A great variety of pull cards have been devised and marketed in various forms, and their greatest popularity has probably been in the field of humorous greeting cards. In many embodiments of such cards, either a message or an illustration or both are visible on an interior leaf through an opening in the front page or cover of the card in its closed position; then upon opening the card, the scene or message inside is shifted by some means operated by the opening of the card to provide a humorous finale in the form of a punch line or startlingly different scene from the original message or scene.
Huber U.S. Pat. No. 2,145,794 describes an embodiment of a greeting card wherein unfolding the folded end of the picture card serves "to present a relatively long and different picture" thereon by turning one panel to the rear where it is no longer visible, uncovering a folded panel, pulling a narrow extension or tongue through a vertical slit from concealment under the front leaf of the card and retaining one of the original front panels in view. Since the tongue is completely covered and thus not visible when the card is folded, it plays no greater part in providing a different picture than the panel that is also covered in the folded position.
Although this interesting pull card has a number of good features, the tongue appears to create some obvious problems and limitations without providing any significant advantages. Difficulties are likely to be encountered in assembling the card, for a narrow tongue or extension is weak and prone to binding, jamming, bunching or tearing in inserting the tongue through the slit in the front leaf thereby creating some production problems. Also there are limits on the length of that slit, and consequently the width of the tongue, if one is to avoid weakening the front leaf to the extent where the slit would tear through to the edge of the leaf. Of course, thicker sheet material can be used to increase the tear strength, but it can also substantially increase the resistance of the material to folding and/or to the sliding motion of the tongue as well as increase the weight and mailing costs. The ends of a slit leave much to be desired as guide means since each end exerts its guiding influence at one point only along the length of the sliding tongue; thus the ends of the slit may tend to display more binding action than guiding action. In addition, the folded end of the card is likely to be rather bulky with its six layers and four fold lines and thus subject to disarrangement, particularly if handled roughly by children.
The present invention is directed at an improved pull card which may be constructed in an extremely simple manner of flexible sheet material which may have a rather wide range of flexural properties; and this card provides extremely smooth and well guided motion in providing movable scenes or messages under one or more display openings in the front leaf or the rear leaf or in both leaves of the card. Moreover, the invention provides for an elongated intermediate leaf to extend beyond the front leaf, allowing several scene display areas to provide a multifaceted scene-changing effect in a simple structure.